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In addition to telescopes, I started looking for cleaning info for vintage photographic lenses. Suggestions for fungus removal included:

Equal parts Peroxide + Ammonia

3% peroxide solution alone

ROR (Residual Oil Remover)

Lighter fluid (Naptha)

"Blue" Windex (my bottle says ammonia free)

Nivea hand creme (someone suggested that the active ingrediant was NaOH)

After reading several blogs and youtube videos, I took the risk and tried the 3% peroxide solution. Because the MkII lenses are bonded doublets, I did not submerge the lenses. I held the lens (with nitrile gloves) and dabbed one surface at a time with a wetted cotton swab. You could "hover" over the surface to keep a local area wetted with a meniscus of fluid. Inevitably some peroxide dribbled onto the glove or over the lens edge. I blotted this with a dry swab when it happened. After a couple of miutes of peroxide exposure, I dried the surface with dry swabs.

I'm very pleased with the outcome. Most of all, there is no sign of new lens or bondline damage from the treatment (sigh of relief). The surfaces are vastly cleaner and clearer than after cleaning with IPA. While there is still some local discoloration (etch or stain) of the surface, the cloudiness and partial surface opacity is gone.The black edging (ink or paint) on the lens outer diameter was not removed. After reassembly, the image sharpness and contrast are much better. I can't say for sure that I didn't remove any coating (or even if the lenses are AR coated, but I think they are...), but the image brightness is better and I'm not seing any dramatic flare.